I would produce the completed front end of a couple of my working designs, say the Short Lady and the Elektra II. The 'front end' would be fully welded, and would include the chamber, plug mount, engine mount lugs, flared intake and starting tube / fuel tube combination (I can easily work out how to mount these on the 'front end' rather than the tailpipe OR make them so they end up being self-aligning). Optionally, two CM-6 spark plugs could be included. It would be up to the purchaser to do the following to finish his engine:
- Make an engine mount block (wood plank w/ drilled holes)
- Make a tailpipe jig block (scrap wood cut to specs)
- Make aluminum heat shield panel (cut aluminum dryer duct to specs and bend)
- Buy a length of 1.25-inch OD antenna mast tubing
- Cut the tubing with square-cut ends to an exact specified length
- Flare BOTH ends slightly - tailpipe finished!
- Mount 'front end' subassembly on mount block
- Mount jig block on mount block
- Place tailpipe on jig block, butted onto 'front end' (front end will 'socket' into front flare of tailpipe tube)
- Tack weld tailpipe onto 'front end'
- Remove tack-welded assembly from mount block / jig block and finish weld, blending front tailpipe flare into rear of 'front end'
- Possibly, weld starting air pipe to engine (I'll eliminate this step if I can)
- Remove jig block
- When cool, re-mount engine to mount block, sandwiching heat shield between engine and block

What do you think?

Here's why I like this plan:
- For me, the production of the front ends would be almost trivial once I have a couple of steel jigs built so I can make consistent pieces
- The cost of materials for the front ends is low, but the perceived value is high since most buyers would see this as the elimination of a LOT of skilled work
- Shipping would be much simpler and cheaper than for finished engines (smaller package, etc.)
- Buyer is left with enough hand work to make the project interesting, but nothing requiring unusual skill level, since the weld area would be essentially self-aligning for tacking
- Buyer gets an easy-starting, good-running finished engine for reasonable cost and effort

Would this work? What's the price point where it would work (i.e. what would it be worth to you if you weren't inclined to build a whole engine from raw sheets and tubes)?

If you would like to send me one free of charge, I would put it together as you have described and test it. Then give you a full review and as much feedback on how it came together and ran. You could use that as a full testimonial review to help you sell them. Also it would tell you if your perception of building it in your mind is really the same as an end user, who has never built one (a working one).

So how about that, I think its a good idea.... I would be willing to even through in a few dollars for shipping. E-mail me if you are interested. :D

I don't want to rain on your parade, but this is the wrong audience for sales of this type, IMHO.
The real problem is finding that audience. Maybe see if an RC distributor would carry it, or ads in the back of Popular Mechanics or something.

Otherwise, do you know many visitors to Jetzilla a: are not "do it yourself designer/builders" or b: unsophisticated enough to buy just because you say it's good?

It's much harder to pull off creating a market for what you love, versus creating a product for an identified market need.

All that being said, it's just got to be hard to sell any motor with only a pound or two of thrust.

Dang911 wrote:If you would like to send me one free of charge, I would put it together as you have described and test it. Then give you a full review and as much feedback on how it came together and ran. You could use that as a full testimonial review to help you sell them. Also it would tell you if your perception of building it in your mind is really the same as an end user, who has never built one (a working one).

So how about that, I think its a good idea.... I would be willing to even throw in a few dollars for shipping. E-mail me if you are interested. :D

Dang -

Please forgive me for not responding right away - I sort of got sidetracked by Mike's response and went off to other things. But yes, that is an idea I had already thought of - I thought I might actually have had a twelve-year old boy and his dad interested, but I never heard back from them after their first inquiry so I never proposed it to them.

Here's what I would be willing to do: I want to build a working prototype of the Sveldt Lady, and have most of the front end parts already made for it. If you want to build it from the kind of "front end kit" I've described, I'll weld it up and send it to you. There would be two things missing that would be part of the standard kit: finished instructions and the spark plugs. Since you've obviously studied my original post, you already have all the instructions you need, except the mounting board and jig block specs and maybe some instructions for starting. You would have to come up with a CM-6 (or other M10x1.0 threaded) plug on your own. My only "special requirement" is that you agree to photograph it step-by-step (digital camera is OK) to the best of your ability and give me rights to use copies of your photos (cropped or otherwise edited by me if needed). You would be credited with the first build and the photos you give me. You can keep the finished engine. For starting, you will need 30 PSI air and a spark source. And a propane supply, of course. I assume you will have no trouble getting the antenna mast tubing locally. If you want to reimburse me for the shipping, that would be nice - it will only amount to five or six dollars, at the most, I'm sure.

If you want to do this, just let me know and email me your COMPLETE mailing address.

Mike Everman wrote:I don't want to rain on your parade, but this is the wrong audience for sales of this type, IMHO.
The real problem is finding that audience. Maybe see if an RC distributor would carry it, or ads in the back of Popular Mechanics or something.

Otherwise, do you know many visitors to Jetzilla a: are not "do it yourself designer/builders" or b: unsophisticated enough to buy just because you say it's good?

It's much harder to pull off creating a market for what you love, versus creating a product for an identified market need.

That's exactly right. I was not implying that my audience would be typical enthusiasts. I would rather appeal to people who are out on the fringes - someone who thinks it might be fun and interesting, but feels that it just takes too much time and trouble to scratch build.

All that being said, it's just got to be hard to sell any motor with only a pound or two of thrust.

It depends on what your market is after. I wouldn't market steel engines as possible flight engines - rather, just something fun and unusual to mess with. People will buy almost anything they think will be fun - if you can afford to get the price point low enough. That's the part that's hard to figure out.

Aside from me building it.....I belong to several r/c clubs locally; I would definitely take the kit to meetings and see what there opinions are about it. Since I got started in pulse-jets, everyone else has wanted one, and showed great interest in mine.....

Ill be honest here... Im a 16 year old kid with a lot off free time on my hands. I can definitely meet all your requirements, and exceed them. I did send you an e-mail, so make sure it didn't go into SPAM.

I have an Olympus 4 mega pixle camera with 10X + 3x digital zoom, and a 52mm UV/IR filter....pretty high tech. If you want I will send you the pics totally raw. They will be huge 2048 X 1536 but I can also make them smaller if you want, like 640 X 480. Also I can send them any format you want. From TIFF, JPEG, GIF, BMP, PNG, PDF......MORE. If I send them to you at full resolution, they will be about 1.5mb each. If I shrink them, I can get them down to 50-200kb per photo at 640 X 480 - 1280 X 960 ressolution. Doesn't matter I have DSL....

Just like Fo Mi Chin II, but this time the spade is flattened to increase the intake area. The tailpipe is just a short piece, since it will be removed to separate the front end. Photo Copyright 2005 Larry Cottrill

Ben wrote:If you're starting with a piece of tailpipe and then cutting it off, it seems like this idea is making more work than it is saving. You're still doing everything necessary for a complete engine, other than the tailpipe flare.

All you're saving is the minor price difference of shipping the front end vs. shipping the entire thing, at the cost of limiting your market to people who can apparently weld thin metal but not very much.

Have faith, Ben. Remember that the point here isn't to perfect how I'd produce them, but rather, to see what the end user thinks about the product and what the perceived value is. Right now, I'm just making the thing the only way I know how to make it, without benefit of nice tooling, jigging, etc.

I need everybody to hold their final judgment until they see how the thing goes together and how that process and the resulting value are perceived by someone who might actually want to do it. That doesn't mean I don't appreciate comments & criticisms, though - keep 'em coming! Just don't make it seem hopeless because of apparent inefficiencies on the production side - there are dozens of ways to approach that.